RatTerm (CSE331 Homework 4)

java.lang.Object
- hw4.RatTerm

```
public final class RatTerm
extends Object
```
RatTerm is an immutable representation of a term in a single-variable polynomial expression. The term has the form C*x^E where C is a rational number and E is an integer.
A RatTerm, t, can be notated by the pair (C . E), where C is the coefficient of t, and E is the exponent of t.
The zero RatTerm, (0 . 0), is the only RatTerm that may have a zero coefficient. For example, (0 . 7) is an invalid RatTerm and an attempt to construct such a RatTerm (through the constructor or arithmetic operations on existing RatTerms) will return the semantically equivalent RatTerm (0 . 0). For example, (1 . 7) + (-1 . 7) = (0 . 0).
(0 . 0), (1 . 0), (1 . 1), (1 . 3), (3/4 . 17), (7/2 . -1), and (NaN . 74) are all valid RatTerms, corresponding to the polynomial terms "0", "1", "x", "x^3", "3/4*x^17", "7/2*x^-1" and "NaN*x^74", respectively.

Field Summary

Fields
Modifier and Type	Field and Description
`static RatTerm`	`NaN` A constant holding a Not-a-Number (NaN) value of type RatTerm
`static RatTerm`	`ZERO` A constant holding a zero value of type RatTerm

Constructor Summary

Constructors
Constructor and Description

RatTerm(RatNum c, int e)

Constructors
Constructor and Description
`RatTerm(RatNum c, int e)`

Method Summary

Methods
Modifier and Type	Method and Description
`RatTerm`	`add(RatTerm arg)` Addition operation.
`RatTerm`	`antiDifferentiate()` Returns the antiderivative of this RatTerm.
`RatTerm`	`differentiate()` Return the derivative of this RatTerm.
`RatTerm`	`div(RatTerm arg)` Division operation.
`boolean`	`equals(Object obj)` Standard equality operation.
`double`	`eval(double d)` Returns the value of this RatTerm, evaluated at d.
`RatNum`	`getCoeff()` Gets the coefficient of this RatTerm.
`int`	`getExpt()` Gets the exponent of this RatTerm.
`int`	`hashCode()` Standard hashCode function.
`boolean`	`isNaN()` Returns true if this RatTerm is not-a-number.
`boolean`	`isZero()` Returns true if this RatTerm is equal to 0.
`RatTerm`	`mul(RatTerm arg)` Multiplication operation.
`RatTerm`	`negate()` Negation operation.
`RatTerm`	`sub(RatTerm arg)` Subtraction operation.
`String`	`toString()` Returns a string representation of this RatTerm.
`static RatTerm`	`valueOf(String termStr)` Builds a new RatTerm, given a descriptive String.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - NaN
```
public static final RatTerm NaN
```
    A constant holding a Not-a-Number (NaN) value of type RatTerm
  - ZERO
```
public static final RatTerm ZERO
```
    A constant holding a zero value of type RatTerm
- Constructor Detail
  - RatTerm
```
public RatTerm(RatNum c,
       int e)
```
    Parameters:
    c - the coefficient of the RatTerm to be constructed.
    e - the exponent of the RatTerm to be constructed.
    Requires:
    c != null
    
    Effects:
    Constructs a new RatTerm t, with t.coeff = c, and if c.equals(RatNum.ZERO), then t.expt = 0, otherwise t.expt = e
- Method Detail
  - getCoeff
```
public RatNum getCoeff()
```
    Gets the coefficient of this RatTerm.
    
    Returns:
    the coefficient of this RatTerm.
  - getExpt
```
public int getExpt()
```
    Gets the exponent of this RatTerm.
    
    Returns:
    the exponent of this RatTerm.
  - isNaN
```
public boolean isNaN()
```
    Returns true if this RatTerm is not-a-number.
    
    Returns:
    true if and only if this has NaN as a coefficient.
  - isZero
```
public boolean isZero()
```
    Returns true if this RatTerm is equal to 0.
    
    Returns:
    true if and only if this has zero as a coefficient.
  - eval
```
public double eval(double d)
```
    Returns the value of this RatTerm, evaluated at d.
    
    Parameters:
    d - The value at which to evaluate this term.
    
    Returns:
    the value of this polynomial when evaluated at 'd'. For example, "3*x^2" evaluated at 2 is 12. if (this.isNaN() == true), return Double.NaN
  - negate
```
public RatTerm negate()
```
    Negation operation.
    
    Returns:
    a RatTerm equals to (-this). If this is NaN, then returns NaN.
  - add
```
public RatTerm add(RatTerm arg)
```
    Addition operation.
    
    Parameters:
    p - The other value to be added.
    
    Returns:
    a RatTerm equals to (this + arg). If either argument is NaN, then returns NaN.
    
    Throws:
    
    IllegalArgumentException - if (this.expt != arg.expt) and neither argument is zero or NaN.
    Requires:
    arg != null
  - sub
```
public RatTerm sub(RatTerm arg)
```
    Subtraction operation.
    
    Parameters:
    p - The value to be subtracted.
    
    Returns:
    a RatTerm equals to (this - arg). If either argument is NaN, then returns NaN.
    
    Throws:
    
    IllegalArgumentException - if (this.expt != arg.expt) and neither argument is zero or NaN.
    Requires:
    arg != null
  - mul
```
public RatTerm mul(RatTerm arg)
```
    Multiplication operation.
    
    Parameters:
    p - The other value to be multiplied.
    
    Returns:
    a RatTerm equals to (this * arg). If either argument is NaN, then returns NaN.
    Requires:
    arg != null
  - div
```
public RatTerm div(RatTerm arg)
```
    Division operation.
    
    Parameters:
    p - The divisor.
    
    Returns:
    a RatTerm equals to (this / arg). If arg is zero, or if either argument is NaN, then returns NaN.
    Requires:
    arg != null
  - differentiate
```
public RatTerm differentiate()
```
    Return the derivative of this RatTerm.
    
    Returns:
    a RatTerm that, q, such that q = dy/dx, where this == y. In other words, q is the derivative of this. If this.isNaN(), then return some q such that q.isNaN()
    Given a term, a*x^b, the derivative of the term is: (a*b)*x^(b-1) for b > 0 and 0 for b == 0 (Do not worry about the case when b < 0. The caller of this function, RatPoly, contains a rep. invariant stating that b is never less than 0.)
  - antiDifferentiate
```
public RatTerm antiDifferentiate()
```
    Returns the antiderivative of this RatTerm.
    
    Returns:
    a RatTerm, q, such that dq/dx = this where the constant of intergration is assumed to be 0. In other words, q is the antiderivative of this. If this.isNaN(), then return some q such that q.isNaN()
    Given a term, a*x^b, (where b >= 0) the antiderivative of the term is: a/(b+1)*x^(b+1) (Do not worry about the case when b < 0. The caller of this function, RatPoly, contains a rep. invariant stating that b is never less than 0.)
  - toString
```
public String toString()
```
    Returns a string representation of this RatTerm.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    A String representation of the expression represented by this.
    There is no whitespace in the returned string.
    If the term is itself zero, the returned string will just be "0".
    If this.isNaN(), then the returned string will be just "NaN"
    The string for a non-zero, non-NaN RatTerm is in the form "C*x^E" where C is a valid string representation of a RatNum (see RatNum's toString method) and E is an integer. UNLESS: (1) the exponent E is zero, in which case T takes the form "C" (2) the exponent E is one, in which case T takes the form "C*x" (3) the coefficient C is one, in which case T takes the form "x^E" or "x" (if E is one) or "1" (if E is zero).
    Valid example outputs include "3/2*x^2", "-1/2", "0", and "NaN".
  - valueOf
```
public static RatTerm valueOf(String termStr)
```
    Builds a new RatTerm, given a descriptive String.
    
    Parameters:
    ratStr - A string of the format described in the @requires clause.
    
    Returns:
    a RatTerm t such that t.toString() = termStr
    Requires:
    'termStr' is an instance of a string with no spaces that expresses a RatTerm in the form defined in the toString() method.
    Valid inputs include "0", "x", and "-5/3*x^3", and "NaN".
  - hashCode
```
public int hashCode()
```
    Standard hashCode function.
    
    Overrides:
    
    hashCode in class Object
    
    Returns:
    an int that all objects equal to this will also.
  - equals
```
public boolean equals(Object obj)
```
    Standard equality operation.
    
    Overrides:
    
    equals in class Object
    
    Parameters:
    obj - The object to be compared for equality.
    
    Returns:
    true iff 'obj' is an instance of a RatTerm and 'this' and 'obj' represent the same RatTerm. Note that all NaN RatTerms are equal.

Class RatTerm

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

NaN

ZERO

Constructor Detail

RatTerm

Method Detail

getCoeff

getExpt

isNaN

isZero

eval

negate

add

sub

mul

div

differentiate

antiDifferentiate

toString

valueOf

hashCode

equals